12V, 9V and even 7.5V switches and routers I encountered so far and tried worked fine directly from VLRA battery with solar charger. That is up to 15V when charging.
But to have peace of mind I put some Pololu modules and a Meanwell DCDC converter RSD-60G-12 (60W Reliable Railway DC-DC Converter, 9-36Vdc input 12V output). Runs well this way for a few years already.